This invention relates to a device for joining two concrete members together.
One such device for joining two concrete members together is disclosed in EP-A-0 651 135, where two sleeves are cast-in respective concrete segments and a ribbed connecting member in one of the sleeves is forced into the other sleeve and is wedged therein by means of an interaction between sloping ribs. Another such device is known from JP 10131306-A.
According to one aspect of the present invention, there is provided a device for joining two concrete members together, the device comprising a female member for anchoring in one of the concrete members to open at a surface thereof and a male member for anchoring in the other of the concrete members, the female member being slotted and undercut and the male member having a head for mating with the female member in its undercut so as to be held therein by a wedging action. The female member is of elastic material and the male member is of elastic material and the head is joined by a web to a body for anchoring the male member, the web being able to slide in the slot and the head being engageable with the female member in its undercut and at least one of the male and female members has a sloping engagement face to provide the wedging action by acting to draw the head further into the female member as the web is moved along the slot.
The members can be concrete segments for forming, for example, a tunnel lining ring or shaft.
According to another aspect of the present invention, there is provided a concrete segment joining system comprising two segment members and a device essentially as just defined for joining the two segment members together.
The male and female members can be made from a high grade elastic polymer material.
Both the male and female members may be provided with the sloping engagement faces to provide the wedging action between them.
The female member may be provided adjacent its slot with an opening to receive the head of the male member so that the head of the male member may be received in the undercut of the female member.
The sloping engagement face on the female member can extend from one end of the slot to the other, increasing in height of slope from an entry end of the slot towards the other end of the slot.
If the male member is provided with the sloping engagement face, this sloping engagement face can increase in height from one side of the male member that is intended to enter the undercut of the female member first towards the other side of the male member.
The female member may be shaped as a double-entry member for the male member. In other words, the female member can be provided with an opening at each end of its slot so as to receive the male member in its undercut from either end of the slot. If the female member is provided with the sloping engagement face, then it is ramped, rising from both ends of the slot, with a flat central land.
The male member may be shaped as a complementary double-entry member for the female member and can be provided with a sloping engagement face that is ramped with a flat central land.